Audi's technical chief Wolfgang Dürheimer has told Autocar that the company is developing a fuel cell-powered A7.

The fuel cell-equipped Audi A7 is due to begin trials at the end of August and is believed to be part of Audi's new 'tron' range of sustainable technologies.

Fuel cells generate electricity and heat through an electro-chemical reaction between a fuel and oxygen. In automotive applications they typically use hydrogen as the fuel and oxygen from the ambient air, so the only by-product is water.

The electricity produced can be used to charge a battery, or to directly drive electric motors for propulsion, while the waste heat can be captured for thermal systems or additional electricity generation via thermocouples.

It's not the first time that Audi or the Volkswagen Group has trialled fuel cells. In 2009, Audi tested the Q5 HFC, which used two high-pressure cylinders of hydrogen to supply a fuel cell powering the Q5 HFC's twin electric motors.

Hydrogen-powered vehicles, which only emit water, are desirable to manufacturers looking to bolster their green credentials. Fuel cell vehicles can also be refuelled quickly, unlike electric vehicles, which take time to charge.

Alternative fuels – including hydrogen and natural gas – are of particular interest to Audi and will remain so until battery technology improves and charging infrastructures expand.

The lack of an established hydrogen infrastructure, however, may prove to be a similar stumbling block for the technology.

If people think that batteries are expensive, temperamental and have short service life just wait until the reality of fuel cells hits home. Oh, and the fuel cell car will need a pretty chunky battery as well.

Then take account of the huge amounts of electricity required to obtain the hydrogen plus the storage and transport problems and you may as well just bung the power into a battery.

If people think that batteries are expensive, temperamental and have short service life just wait until the reality of fuel cells hits home. Oh, and the fuel cell car will need a pretty chunky battery as well.

Then take account of the huge amounts of electricity required to obtain the hydrogen plus the storage and transport problems and you may as well just bung the power into a battery.

Couldn't have put it better myself. BMW tried hydrogen power in 2007 and look where it got them, battery/hybird power in 2013/14

The car can be fed natural gas and an onboard reformer extracts the hydrogen. All the infrastructure problem is solved and the advantage of a fuel cell over an ICE is lower emissions due to the absence of high-pressure explosion and a way lower waste in the form of heat. Not to mention that a fuel cell is a simpler device with no rotation masses, oil for lubrification, nor nocive exhaust emissions.

I am in fact amazed that resources are diverted to battery powered cars, not fuel cell ones.

Yes, but reformers are not straighforward devices to get right either - delicate catalysts just waiting to be permanently shagged by the most minute bit of contamination in the fuel which will then immediately knacker the fuel cell itself. Not to mention that it will probably be necessary to clean nasty hydrocarbons out of the exhaust like residual methane and carbon monoxide. Potentially horrendous corrosion issues to deal with too.

Sadly hydrogen like electricity powered cars are just fossil fuelled cars in diguise.

Unless the electricity or hydrogen comes from a renewable source, very unlikely for the next 30 years or so, thay are really just fossil fuelled cars.

Most hydrogen is produced by using methane , natural gas, just like much electricity is produced by natural gas.

sadly some of the older, bigger buffoons at Autocar seem to think that a hugely complicated fuel cell car with zero infrastructure and all the inherent problems of current fossil products (eg the fact they explode) are a long term answer.

You just have to hope that if they keep having their lunches bought for them by the industry in exchange for more PR nonsense spouted in print here and in the magazine they'll go pop - much like hydrogen does.

The simple fact is that if hydrogen is a supposed answer to the fossil fuel problem it a) clearly isn't, as you state, and b) will not have widespread availability for probably 50 years. If ever.

How much money are VW group blowing on these hydrogen car projects? How much of that is taxpayer money?

It's hilarious they announce this, when today Tesla announced by 2015 there's going to be a network of their supercharger charging stations that will cover 98% of the states. And they will be free to use for life for all Tesla owers...